Printing-paper.



rrn Smarts Patented June 20, 190 5.

JOSEF VON SCHMAEDEL, OF MUNICH, GERMANY.

PRINTING-PAPER.

SPECIFICATION formingpart of Letters Patent No. 792,932, dated (Tune 20,1905.

Application filed April 19, 1904. Serial No. 203,924.

To all whom it may concern:

Be it known that I, J OSEF VON SonMAnDnL, manufacturer, a subject of theGerman Emperor and of the King of Bavaria, and a resident of Munich, inthe Kingdom of Bavaria, German Empire, have invented new and usefulImprovements in Printing-Paper, of which the following is aspecification.

In order to impart toprinting-paper the high degree of capacity for theabsorption of printing-ink required by the modern processes ofreproduction, it has hitherto been usual to add certain suitablesubstances to the pulp or.

to provide the surface of the finished paper with a suitable coating,the said surface being rendered smooth and close-grained by means ofglazing. The object of the present invention is to remove certaindisadvantages of the old methods referred to and to impart to the papera very high degree of capacity for absorption and also increasedflexibility and suitability for being glazed. This is effected by addingto the paper at any stage of its manufacture one of thesubstancesbelonging to the glucoside series and soluble in wateras, for instance,esculin or saponin, the latter being preferably used. This substance,(saponin,) dissolved in water in the proportion of one to five gramssaponin to one liter water, may be mixed with the pulp in the rag-engineor the vat, or the half-finished or finished paper can be drawn througha solution of the said substance in such a manner that the fibers of thepaper become saturated therewith. With all these different methods ofperforming the process a five-per-cent. solution of the glucoside isusually sufficient for the purpose in view. Solutions of other strengthscan, however, of course be used for paper intended for specialpurposes.-

It is not essential to use only one substance of the glucoside series ineach case. The substances may be mixed in any desired manner, providedthey remain soluble in water. By using these glucosides which aresoluble in water-more particularly saponin for the manufacture ofprinting-paper the advantage is obtained that the paper fibers arecompletely saturated with the solution, and thus rendered highlyflexible or pliant and capable of being glazed. During the drying of thepaper the glucosides are deposited between the fibers in a state ofinfinitely-fine distribution and impart to the paper a close structure,which is of great advantage for printing. The fiber thus treatedthat isto say, saturated with saponin solution, for instance,and then driedreadily absorbs printing-ink and is particularly well adapted to takeink from the forms.

It may be mentioned that glocoside solutions, more particularly saponinsolutions, even when very weak have the capacity of holding pulverizedinsoluble substances in suspension for a very long time. This is ofgreat importance when saponin is introduced into the rag-engine or vat.A saponin solution can, for instance, be directly mixed with a resinsolution, so that an extremely finely divided resin emulsion is obtainedin which neither lumps nor deposits are formed. This is also the case ifa bath of saponin solution is used to which resin emulsion is added. Incase the saponin is added to a solution or emulsion of resin or otherequivalent material,.as fat, oil, Wax, &c., a proportion of one kilogramresin, &c., to fifty to six hundred grams saponin is preferably used.The finely-cut fiber of the pulp also remains in finely-dividedsuspension in the saponin solution, by which means the homogeneousnessof the paper is considerably increased.

Having now particularly described and aseertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. Printing-paper containing a soluble glucoside such assaponin.

2. Printing-paper containing a soluble glucoside such as saponin in theproportion of one hundred kilograms paper-pulp to one hundred to twohundred grams saponin.

3. Printing-paper containing a soluble glucoside such as saponinintroduced in combination with a resin emulsion containing fifty to sixhundred grams saponin to one kilogram resin.

In testimony whereof I have signed my name to this specification inpresence of two subscribing witnesses.

J OSEF VON SGHMAEDEL.

Witnesses:

ULYssns J. BYWATER, IVIATHILDE HELD.

